The present invention relates to a clamp for fastening a trackball-containing shell to laptop computer keyboards and, more particularly, to a clamp having a replaceable first clamping element cooperating with a spring-biased second clamping element for clamping to the keyboard and a button for pressing the spring-biased second clamping element with respect to the first clamping element before the use thereof.
At the time being, laptop computers are widely used to help deal with business outside offices because of their size and portability. For drawing, a laptop computer is desired to incorporate a trackball in order to move a cursor more readily on a screen. Generally, as laptop computers and trackballs are used outside offices, it is difficult to find plane surfaces to place the trackballs, especially when used in vehicles. Therefore, a trackball encompassed in a shell is usually sold with a clamp which is used for binding the shell to a keyboard, so that the trackball is maintained in a stable position relative to the keyboard.
Conventionally, a clamp bearing a shell which encompasses a trackball is secured to a keyboard with screws. The screws must be disengaged from the keyboard to release the clamp from the keyboard, so that the laptop computer, the keyboard, and the trackball can be packed in a business case more easily. It is relatively inconvenient to bring screw drivers to disengage the screws from the keyboard. Furthermore, a clamp made by a certain manufacturer usually does not fit a keyboard made by another manufacturer.
In the present inventor's co-pending U.S. patent application No. 07/882,485, a clamp is used for fastening a shell which encompasses a trackball to a keyboard of a laptop computer. The clamp has a tray having a dovetail for engaging with a dovetail slot of the shell, a replaceable first clamping element with a first jaw to be inserted in a clearance between keys and a margin of the keyboard, and a spring-biased second clamping element for abutting the margin, so that the first clamping element cooperates with the spring-biased second clamping element to clamp the margin, thereby maintaining the shell in a stable position relative to the keyboard. Although the spring-biased second clamping element and the first clamping element firmly clamp the margin, it is inconvenient to press the spring-biased second clamping element away from the first clamping element before the use thereof.
The present invention is intended to overcome the above-mentioned drawbacks.